Study Effect of Evening Primrose Oil Supplement on Type 2 Diabetes Mellitus - Associated Metabolic Parameters

Natural products are reported to be useful for controlling or preventing T2DM as an anti-inflammatory, AMPK activators, insulin secretion stimulators, alpha-glucosidase / disaccharidase or amylase inhibitors. Evening primrose oil (Oenothera biennis) is a substantial source of omega-6 essential fatty acids, mostly gamma-linolenic acid (GLA). The activity of Δ-6-desaturase enzyme responsible to convert linolenic acid (LA) to forms GLA is compromised in patients with type 2 diabetes. Accordingly, this study aimed to evaluate the effect of evening primrose oil in amelioration metabolic parameters of type 2 diabetes mellitus. Twenty six overweight or obese patients newly diagnosed with type 2 diabetes were enrolled. Thirteen patients received metformin 500 mg tablets twice daily alone (as a conventional therapy) for 3 month therapy, and 13 patients received metformin 500 mg plus evening primrose oil 2 gm capsule twice daily. Serum fasting glucose, total cholesterol, triglycerides, high density lipoprotein-cholesterol (HDL-C), low density lipoprotein cholesterol, very low density lipoprotein cholesterol, fasting serum insulin (FSI) was measured. Insulin resistance and β-cell function was determined by using homeostatic model assessment (HOMA).  There was statistically significant elevation in baseline level of fasting serum glucose, glycated hemoglobin (HbA1c), total cholesterol, low density lipoprotein-cholesterol (LDL-C), fasting serum insulin, insulin resistance (HOMA- IR), and in both patient groups 1 and 2 compared to control subjects, (P< 0.001). High reduction in these parameters post treatment was found in both patient groups compared to pre treatment level, significantly with fasting serum insulin in group 2 patients (P< 0.001). Inversely, lower levels were seen in HDL-C, HOMA-B, significantly elevated post treatment in both groups. No difference was found in triglyceride and VLDL-C in both patient groups compared to control subjects, but significantly reduced post treatment. In conclusion, early intervention with natural oil rich in gamma linolenic acid with traditional hypoglycemic drugs can improve therapeutic outcome and represent a promising strategy to slow the progression of diabetes complications.